Bigger cows output more methane Teo. There's not much you can do to drastically reduce methane emissions per kg of dead cow flesh. Confining them and not letting them move fattens them up a little faster relative to food intake, but methane remains roughly proportional to calorie intake.
teo123 wrote: ↑Sat Jan 25, 2025 11:04 am
But the problem is that many vegans are claiming that grass-fed cows emit around 3 times as much methane per a litre of milk than grain-fed cows.
What is that based on?
Almost all cows are pasture or hay fed for the first part of their lives. I know of no protocol in actual use commercially that is 100% grain (as opposed to hay silage which may be from a grain producing plant's leaves) from birth to slaughter. Finishing is the last fattening up period which relies more on grains (usually not 100%, but it's a lot), and which is roughly half the duration of the grazing period.
My understanding is that actual methane emissions per day may be slightly lower for grass, probably due to lower calorie consumption, but because it requires more days to grow a cow to slaughter size on grass that total methane emissions are actually a little higher. I don't think I've ever heard anything like tree times higher.
IIRC methane production is around 20% higher for pasture finished cattle. It also requires much more land, so we can look at the opportunity cost of carbon sequestration from not allowing that land to rewild, but that's aside from the point on methane.
I don't think these LCAs account for methane released by manure lagoon strategies vs. more aerobic decomposition of dispersed feces. I would be a little surprised but not completely shocked if they ended up being about the same in terms of methane output.
teo123 wrote: ↑Sat Jan 25, 2025 11:04 amBut it's even more important to be able to detect situations when the experts are not actually saying what the politicians and activists are saying that they are saying.
Figure out how to find credible sources of expert consensus, don't try to do your own statistical analysis.
teo123 wrote: ↑Sat Jan 25, 2025 11:04 am
And it's not me who noticed the problem, it's the Quora user called Malcolm Forster who informed me of the problem.
Just as recovering substance abusers should not associate with other substance abusers, you should not be associating with conspiracy theorists.
Methane concentration in the atmosphere is increasing over time. It reaches equilibriums pretty fast in geological time, it just rises with a new source until the equilibrium is reached. If it's going up, so is production. It doesn't mean it's all directly anthropogenic (although a lot of that recent increase is probably indirectly so, fueled by global warming increasing the output of other sources like wetlands and melting permafrost), but you trying to data crunch it away or find any kind of answer in mathematics is very much like your weird atmospheric refraction theories in flat-Earthism. Mathematical analysis is not going to help you glean any new insight. Experts are not mathematically incompetent, but beyond that it's pretty straight forward- A positive slope means a new or increasing source has shown up/is showing up or a methane sink has been lost/is being lost, that's it. The data is not so clean as to give the equivalent of a forensic time of death in year month day and hour. If you had better direct data on anthropogenic sources you might be able to subtract that and then correlate natural sources to temperature rises to do better predictions, but that's a kind of data we're lacking so there's nothing you can do. It's something experts are working on. You're not one of them.
It's embarrassing that you're trying to write papers on this, that's not the way to find out something. Scientific paper submissions are not your personal Quora.
Anthropogenic methane emissions from animal agriculture are increasing because beef consumption is still increasing, better management is practically a rounding error. Given the increase, I don't even think perfect management of manure (the biggest factor in animal ag. that is within human control, aside from just not eating meat) is going to be enough to see any net reductions.
Whether methane emissions from landfills and the oil industry (including old open wells) are increasing or decreasing is a better question, because good management in that domain returns enormous dividends. This is a matter of ongoing empirical study. You will need to stay tuned.
The total is increasing anyway. If we've reduced methane emissions from direct sources, indirect ones have taken up the balance which is very concerning. This is why this is such an urgent matter of research. But you're not contributing here. You have to make on the ground measurements, not Java script.